1. Field of the Invention
The present invention relates to a vehicle headlamp that is capable of causing light from a semiconductor-type light source to be incident to a lens, illuminating the incident light from the lens forward of a vehicle, as a predetermined light distribution pattern, and switching the light distribution pattern.
2. Description of the Related Art
A vehicle headlamp of such type is conventionally known (for example, Japanese Unexamined Patent Application Publication No. 2010-153181). Hereinafter, the conventional vehicle headlamp will be described.
The conventional vehicle headlamp is provided with a lens, a prism member, and a switching device. In addition, the conventional vehicle headlamp is provided in such a manner that light from a semiconductor-type light source is caused to be directly incident to a lens, whereby a light distribution pattern for low beam that serves as a first light distribution pattern can be obtained, and when a prism member is positioned between the semiconductor-type light source and the lens by means of the switching device, a light distribution pattern for high beam that serves as a second light distribution pattern can be obtained.
However, the conventional vehicle headlamp is also provided in such a manner all of the light beams from the semiconductor light source is caused to be transmitted through the prism member, and the transmitted light beams are switched from a light distribution pattern for low beam to a light distribution pattern for high beam. Therefore, in the conventional vehicle headlamp, there may be a case in which the amount of light becomes insufficient in a portion of the light distribution pattern for high beam that serves as the second light distribution pattern that is obtained by transmitting all of the light beams from the semiconductor light source through the prism member.